Various types of display have conventionally been developed as products that each form an image using pixels as a displaying means to display information or a video image. For example, a display is common whose each one pixel is configured by three primary-color sub pixels that are those of red (R), green (G), and blue (B) and the display thereby executes color display. These sub pixels are usually realized by using color filters. In such a color display technique, expansion of color reproducibility has recently been considered to improve the display appearance quality.
Whereas, a what-is-called multi-primary-color display has been developed that is adapted to expand regions in a chromaticity diagram for chromatic colors and to improve brightness efficiency by increasing the number of the primary colors to four or more primary colors by using new colors other than the three primary colors of “R”, “G”, and “B”. Displays under consideration include, for example, a display employing an RGBY pixel configuration formed by adding Y (yellow) to R, G, and B, and a display employing an RGBW pixel configuration formed by adding W (white) to R, G, and B.
On the other hand, a sub-pixel sampling technique is present according to which sampling is executed for an input video image signal for each of sub pixels constituting a pixel to execute high-definition video-image expression by improving the resolution property of a display. The sub-pixel sampling technique is a technique of regarding each of sub pixels as one pixel for, for example, pixels each configured by the three sub pixels of R, G, and B, and reproducing brightness for each of the sub pixels. In this case, when the R, G, and B are disposed in the horizontal direction, the sampling is executed using the sampling frequency in the horizontal direction that is increased to a sampling frequency three times as high as the conventional sampling frequency. The R, G, and B sub pixels are driven based on signals sampled that correspond to the sub pixels.
Concerning techniques of improving the resolution property, for example, Patent Document 1 discloses a technique that aims at improving the resolution of a black-and-white text or a graphic image rendered, and narrowing color fringes. According to this technique, RGB image data is displayed that is produced by interleaving a gray scale image to an image that is three times as long as its original length in the horizontal direction and low-pass-filtering the resultant image.